Thanks, I had been previously using "drm.edid_firmware=edid/1280x1024.bin" in /etc/default/grub which then failed on upgrade to Proxmox 9 and generated additional errors. Removing and replacing with "video=HDMI-A-1:1920x1080@60e" followed by...
How can I install that, if I start on trixie?
"To ensure your system trusts the new APT archive keyring for our Debian Trixie-based releases, install the proxmox-archive-keyring package before switching the repos to Trixie."
apt install...